I am aware of the legal part in my state. Some have mentioned that part of their training /practice includes shoots of 50yds or more as part of sd. Where I live that's likely murder. I also know that some one intent on getting to you to harm you will close a lot of ground fast. The question was asked as a personal what would you do. Personally if I had to choose I'd say 30ft is around the time to hit the action button for me but, truth is you never know when.